Fibers for artificial hair and hair accessory

ABSTRACT

A fiber for artificial hair, having a base fiber and a metal salt of a polymer compound that is present in at least a part of a surface of the base fiber, in which the metal salt contains at least one metal selected from the group consisting of silver, zinc, and copper. A headdress article having the fiber for artificial hair.

TECHNICAL FIELD

The present invention relates to a fiber for artificial hair, a headdress article, and the like.

BACKGROUND ART

Fibers for artificial hair (fibers used for artificial hair) can be used for headdress articles. In Patent Literature 1 below, a technique of treating a base fiber using a fiber treating agent is disclosed.

CITATION LIST Patent Literature

-   Patent Literature 1: Japanese Unexamined Patent Publication No.     2002-285470

SUMMARY OF INVENTION Technical Problem

Since consumers using headdress articles do not frequently wash the headdress articles in some cases, the scalp or the headdress article cannot be maintained cleanly, and bacteria may grow, which causes malodor or the like. Therefore, fibers for artificial hair used for headdress articles are required to have antibacterial activity.

An object of an aspect of the present invention is to provide a fiber for artificial hair having antibacterial activity. An object of another aspect of the present invention is to provide a headdress article having such a fiber for artificial hair.

Solution to Problem

An aspect of the present invention relates to a fiber for artificial hair, having a base fiber and a metal salt of a polymer compound that is present in at least a part of a surface of the base fiber, in which the metal salt contains at least one metal selected from the group consisting of silver, zinc, and copper.

Another aspect of the present invention relates to a headdress article having the above-mentioned fiber for artificial hair.

Advantageous Effects of Invention

According to an aspect of the present invention, a fiber for artificial hair having antibacterial activity can be provided. According to another aspect of the present invention, a headdress article having such a fiber for artificial hair can be provided.

DESCRIPTION OF EMBODIMENTS

Hereinafter, embodiments of the present invention will be described in detail.

The expression “A or more” of a numerical value range means A and a range of more than A. The expression “A or less” of a numerical value range means A and a range of less than A. With regard to a numerical value range described stepwise in the present specification, the upper limit value or the lower limit value of the numerical value range at a certain stage can be optionally combined with the upper limit value or the lower limit value of the numerical value range of another stage. With respect to a numerical value range described in the present specification, the upper limit value or the lower limit value of the numerical value range may be substituted with the values shown in Experimental Examples. The expression “A or B” may include either A or B or may include both of them. Unless particularly stated otherwise, the materials described as examples in the present specification can be used singly or in combination of two or more kinds thereof. In a case where a plurality of substances corresponding to each component in a composition is present, unless particularly stated otherwise, the content of each component in the composition means the total amount of the plurality of substances present in the composition. The term “step” means not only an independent step, but even in a case where a step cannot be clearly distinguished from another step, the step is included in the present term as long as the predetermined action of the step is achieved. The term “(meth)acrylic acid” means at least one of acrylic acid and methacrylic acid corresponding thereto.

A fiber for artificial hair of the present embodiment has a base fiber (fibrous base) and a metal salt (hereinafter, referred to as “metal salt A”) of a polymer compound that is present in at least a part of a surface of the base fiber, in which the metal salt A contains at least one metal (hereinafter, referred to as “metal A”) selected from the group consisting of silver, zinc, and copper. The fiber for artificial hair of the present embodiment can be used as artificial hair and can also be used in order to obtain artificial hair. The fiber for artificial hair of the present embodiment may be a fiber obtained after a stretching treatment, or may be an unstretched fiber.

The fiber for artificial hair of the present embodiment has antibacterial activity and has antibacterial activity against Escherichia coli. Furthermore, the fiber for artificial hair of the present embodiment can also have antibacterial activity against Staphylococcus aureus.

Examples of the base fiber material include a vinyl chloride-based resin, a polyester-based resin, and a polyamide-based resin. The base fiber may contain a mixture of a vinyl chloride-based resin and a component that can form a polymer alloy with the vinyl chloride-based resin. Examples of the component that can form a polymer alloy with the vinyl chloride-based resin include an ethylene-vinyl acetate copolymer (EVA), an acrylonitrile-butadiene rubber (NBR), a thermoplastic polyurethane (TPU), a polyester-based thermoplastic elastomer (TPEE), a methyl methacrylate-butadiene-styrene resin (MBS), an acrylonitrile-butadiene-styrene resin (ABS), an acrylonitrile-styrene copolymer (AS), and polymethyl methacrylate (PMMA).

The base fiber preferably contains a vinyl chloride-based resin from the viewpoint of excellent processability for a headdress article. The vinyl chloride-based resin is a polymer having a structural unit derived from vinyl chloride, and is a polymer having vinyl chloride as a monomer unit. The vinyl chloride-based resin can be obtained by bulk polymerization, solution polymerization, suspension polymerization, emulsion polymerization, or the like, and is preferably obtained by suspension polymerization from the viewpoint of excellent initial colorability of fibers or the like.

Examples of the vinyl chloride-based resin include a homopolymer of vinyl chloride (homopolymer, polyvinyl chloride) and copolymers of vinyl chloride and other monomer, and a mixture thereof may be used. Examples of the copolymers of vinyl chloride and other monomer include a copolymer of vinyl chloride and vinyl esters (such as a vinyl chloride-vinyl acetate copolymer and a vinyl chloride-vinyl propionate copolymer); a copolymer of vinyl chloride and a (meth)acrylic acid compound (such as (meth)acrylic acid and a (meth)acrylic acid ester) (such as a vinyl chloride-butyl acrylate copolymer and a vinyl chloride-2-ethylhexyl acrylate copolymer); a copolymer of vinyl chloride and olefins (such as a vinyl chloride-ethylene copolymer and a vinyl chloride-propylene copolymer); and a vinyl chloride-acrylonitrile copolymer. The vinyl chloride-based resin may not have a structural unit derived from a (meth)acrylic acid compound. In the copolymer, the content of the monomer different from vinyl chloride can be determined according to required qualities such as molding processability and fiber characteristics. The vinyl chloride-based resin preferably includes at least one selected from the group consisting of a homopolymer of vinyl chloride and a vinyl chloride-acrylonitrile copolymer, from the viewpoint of excellent processability for a headdress article.

The content of the vinyl chloride-based resin in the base fiber may be 50% by mass or more, 70% by mass or more, 90% by mass or more, 95% by mass or more, 98% by mass or more, or 99% by mass or more, based on the total mass of the base fiber. The base fiber may be an embodiment composed of only a vinyl chloride-based resin (substantially 100% by mass of the base fiber is a vinyl chloride-based resin).

Examples of the polyester-based resin include polyethylene terephthalate, polybutylene terephthalate, polyethylene-2,6-naphthalate, and polymethylene terephthalate.

Examples of the polyamide-based resin include nylon 6, nylon 66, nylon 11, nylon 12, nylon 6/10, and nylon 6/12.

From the viewpoint that the stretch ratio can be made small in order to obtain a fiber for artificial hair with a finer fiber degree, and that luster is less likely to be generated in the fiber for artificial hair after a stretching treatment, the average fineness of the base fibers at the time of being unstretched is preferably 300 decitex or less, and more preferably 200 decitex or less.

The metal salt A is present in at least a part of the surface of the base fiber, and for example, is attached to at least a part of the surface of the base fiber. The metal salt A can be used as an antibacterial agent. By the metal salt A having a polymer chain, the metal salt A is likely to be attached to the surface of the base fiber. The metal salt A contains at least one metal A selected from the group consisting of silver, zinc, and copper, and preferably contains silver from the viewpoint of easily improving the antibacterial activity.

The polymer chain of the metal salt A can have structural units derived from various monomers. Examples of monomers that provide the polymer chain include (meth)acrylic acid, a (meth)acrylic acid ester (such as poly(alkylene glycol) alkyl ether (meth)acrylate (poly(ethylene glycol) methyl ether (meth)acrylate, etc.) and butyl (meth)acrylate), a vinyl compound (such as vinylimidazole (1-vinylimidazole, etc.) and vinylpyridine (4-vinylpyridine, etc.)), ethylene, butadiene, 2,3-dichloro-1,3-butadiene, 1-chloro-1,3-butadiene, isoprene, and styrene. The polymer chain of the metal salt A may have a structural unit derived from a (meth)acrylic acid ester (may have a (meth)acrylic acid ester as a monomer unit), or may have a structural unit derived from a (meth)acrylic acid ester and a structural unit derived from a vinyl compound (may have a (meth)acrylic acid ester and a vinyl compound as monomer units).

The content of the metal A, the content of silver, the content of zinc, or the content of copper is preferably 1.0×10⁻⁵% by mass or more, 3.0×10⁻⁵% by mass or more, 5.0×10⁻⁵% by mass or more, 7.0×10⁻⁵% by mass or more, 1.0×10⁻⁴% by mass or more, 2.0×10⁻⁴% by mass or more, 3.0×10⁻⁴% by mass or more, 4.0×10⁻⁴% by mass or more, 5.0×10⁻⁴% by mass or more, 7.0×10⁻⁴% by mass or more, 1.0×10⁻³% by mass or more, 3.0×10⁻³% by mass or more, or 5.0×10⁻³% by mass or more, based on the total mass of the fiber for artificial hair, from the viewpoint of easily improving the antibacterial activity.

According to the finding of the present inventors, the tactile sensation of the fiber for artificial hair is deteriorated as the content of the metal A, the content of silver, the content of zinc, or the content of copper increases. Therefore, the content of the metal A, the content of silver, the content of zinc, or the content of copper is preferably 1.0×10⁻²% by mass or less, 7.0×10⁻³% by mass or less, 5.0×10⁻³% by mass or less, 3.0×10⁻³% by mass or less, 1.0×10⁻³% by mass or less, 7.0×10⁻⁴% by mass or less, 5.0×10⁻⁴% by mass or less, 4.0×10⁻⁴% by mass or less, 3.0×10⁻⁴% by mass or less, 2.0×10⁻⁴% by mass or less, 1.0×10⁻⁴% by mass or less, 7.0×10⁻⁵% by mass or less, 5.0×10⁻⁵% by mass or less, or 3.0×10⁻⁵% by mass or less, based on the total mass of the fiber for artificial hair, from the viewpoint of easily obtaining excellent tactile sensation (such as a slipping property improving effect or a stickiness suppressing effect) of the fiber for artificial hair.

The content of the metal A, the content of silver, the content of zinc, or the content of copper is preferably 1.0×10⁻⁵ to 1.0×10⁻²% by mass, 1.0×10⁻⁵ to 5.0×10⁻³% by mass, 5.0×10⁻⁵ to 5.0×10⁻³% by mass, 5.0×10⁻⁵ to 4.0×10⁻⁴% by mass, or 1.0×10⁻⁴ to 4.0×10⁻⁴% by mass, from the viewpoint of achieving both the antibacterial activity and the tactile sensation at a high level. The content of the metal A is the total amount of silver, zinc, and copper.

The fiber for artificial hair of the present embodiment may have an antistatic agent (excluding a component corresponding to the metal salt A) that is present in at least apart of the surface of the base fiber. By using the antistatic agent, the antistatic property can be improved. The antistatic agent is attached, for example, to at least a part of the surface of the base fiber.

Examples of the antistatic agent include an ionic liquid, an anionic antistatic agent, a cationic antistatic agent, and a non-ionic antistatic agent.

As the ionic liquid, a liquid compound salt composed of only ions (cation and anion) can be used. Examples of the cation of the ionic liquid include an ammonium ion, an imidazolium ion, a pyridinium ion, a pyrrolidinium ion, a pyrrolinium ion, a piperidinium ion, a pyrazinium ion, a pyrimidinium ion, a triazolium ion, a triazinium ion, a quinolinium ion, an isoquinolinium ion, an indolinium ion, a quinoxalinium ion, a piperazinium ion, an oxazolinium ion, a thiazolinium ion, and a morpholinium ion. Examples of the anion of the ionic liquid include a halogen-based ion, a boron-based ion, a phosphorus-based ion, and a sulfonate anion. As the ionic liquid, an amine salt containing ions having an amino group can be used.

Examples of the anionic antistatic agent include a sulfonate salt, a sulfate ester salt, and a phosphate ester salt (for example, a polyoxyalkylene alkyl ether phosphate salt).

Examples of the cationic antistatic agent include a quaternary ammonium salt, a guanidine compound, an imidazoline compound, and a pyridinium compound.

Examples of the non-ionic antistatic agent include a polyhydric alcohol (for example, polyalkylene glycol such as polyethylene glycol), a fatty acid ester of polyhydric alcohol, and an alkylene oxide polymer (for example, a copolymer of propylene oxide and ethylene oxide).

The content of the antistatic agent is preferably in the following range based on the total mass of the fiber for artificial hair. The content of the antistatic agent is preferably 0.010% by mass or more, 0.015% by mass or more, 0.020% by mass or more, 0.030% by mass or more, 0.050% by mass or more, 0.100% by mass or more, 0.200% by mass or more, 0.250% by mass or more, 0.300% by mass or more, 0.350% by mass or more, 0.400% by mass or more, 0.500% by mass or more, or 0.600% by mass or more, from the viewpoint of easily improving the antistatic property. The content of the antistatic agent is preferably 1.000% by mass or less, 0.800% by mass or less, 0.600% by mass or less, 0.500% by mass or less, 0.400% by mass or less, 0.350% by mass or less, 0.300% by mass or less, 0.250% by mass or less, 0.200% by mass or less, 0.100% by mass or less, 0.050% by mass or less, 0.030% by mass or less, 0.020% by mass or less, or 0.015% by mass or less, from the viewpoint of easily obtaining excellent tactile sensation (such as a slipping property improving effect or a stickiness suppressing effect) of the fiber for artificial hair. From these viewpoints, the content of the antistatic agent is preferably 0.010 to 1.000% by mass, 0.010 to 0.500% by mass, 0.020 to 0.500% by mass, 0.020 to 0.400% by mass, 0.020 to 0.300% by mass, 0.050 to 0.300% by mass, or 0.200 to 0.300% by mass.

The content of the antistatic agent is preferably in the following range with respect to 100 parts by mass of the metal A. The content of the antistatic agent is preferably 1.0×10³ parts by mass or more, 3.0×10³ parts by mass or more, 5.0×10³ parts by mass or more, 6.0×10³ parts by mass or more, 8.0×10³ parts by mass or more, 1.0×10⁴ parts by mass or more, 2.0×10⁴ parts by mass or more, 4.0×10⁴ parts by mass or more, 5.0×10⁴ parts by mass or more, 6.0×10⁴ parts by mass or more, 8.0×10⁴ parts by mass or more, 1.0×10⁵ parts by mass or more, 1.5×10⁵ parts by mass or more, 2.0×10³ parts by mass or more, 3.0×10⁵ parts by mass or more, 4.0×10⁵ parts by mass or more, 5.0×10³ parts by mass or more, or 8.0×10⁵ parts by mass or more, from the viewpoint of easily improving the antistatic property. The content of the antistatic agent is preferably 1.0×10⁶ parts by mass or less, 8.0×10⁵ parts by mass or less, 5.0×10⁵ parts by mass or less, 4.0×10⁵ parts by mass or less, 3.0×10⁵ parts by mass or less, 2.0×10⁵ parts by mass or less, 1.5×10⁵ parts by mass or less, 1.0×10⁵ parts by mass or less, 8.0×10⁴ parts by mass or less, 6.0×10⁴ parts by mass or less, 5.0×10⁴ parts by mass or less, 4.0×10⁴ parts by mass or less, 2.0×10⁴ parts by mass or less, 1.0×10⁴ parts by mass or less, 8.0×10³ parts by mass or less, 6.0×10³ parts by mass or less, or 5.0×10³ parts by mass or less, from the viewpoint of easily obtaining excellent tactile sensation (such as a stickiness suppressing effect) of the fiber for artificial hair. From these viewpoints, the content of the antistatic agent is preferably 1.0×10³ to 1.0×10⁶ parts by mass, 1.0×10³ to 5.0×10⁵ parts by mass, 1.0×10⁴ to 5.0×10⁵ parts by mass, 1.0×10⁴ to 4.0×10⁵ parts by mass, or 5.0×10⁴ to 4.0×10⁵ parts by mass.

The fiber for artificial hair of the present embodiment may have a silicone compound (excluding a component corresponding to the metal salt A or the antistatic agent) that is present in at least a part of the surface of the base fiber. The silicone compound can be used as a tactile sensation adjuster. By using the silicone compound, the slipping property of the fiber for artificial hair can be improved. The silicone compound is attached, for example, to at least a part of the surface of the base fiber.

The silicone compound preferably includes amino-modified silicone (an amino-modified silicone compound) from the viewpoint of easily improving the slipping property of the fiber for artificial hair. By using the amino-modified silicone, excellent compatibility and dispersibility with respect to the antistatic agent (for example, an amine salt containing ions having an amino group) can also be obtained. The amino-modified silicone is a silicone compound in which the amino group is bonded to a silicone skeleton directly or via a substituent.

Examples of the silicone compound not corresponding to the amino-modified silicone include silicone oils such as straight silicone oils and modified silicone oils. Examples of the straight silicone oils include dimethyl silicone oils, methyl phenyl silicone oils, and methyl hydrogen silicone oils. Examples of the modified silicone oils include epoxy-modified silicone oils, silanol-modified silicone oils, acryl-modified silicone oils, and polyether-modified silicone oils.

The content of the silicone compound is preferably in the following range based on the total mass of the fiber for artificial hair. The content of the silicone compound is preferably 0.001% by mass or more, 0.005% by mass or more, 0.006% by mass or more, 0.010% by mass or more, 0.012% by mass or more, 0.020% by mass or more, 0.050% by mass or more, 0.060% by mass or more, 0.100% by mass or more, 0.120% by mass or more, 0.150% by mass or more, or 0.180% by mass or more, from the viewpoint of easily obtaining excellent tactile sensation (such as a slipping property improving effect) of the fiber for artificial hair. The content of the silicone compound is preferably 1.000% by mass or less, 0.500% by mass or less, 0.400% by mass or less, 0.300% by mass or less, 0.250% by mass or less, 0.200% by mass or less, or 0.180% by mass or less, from the viewpoint of easily obtaining excellent tactile sensation (such as a stickiness suppressing effect) of the fiber for artificial hair. From these viewpoints, the content of the silicone compound is preferably 0.001 to 1.000% by mass, 0.001 to 0.500% by mass, 0.010 to 0.500% by mass, 0.010 to 0.300% by mass, 0.050 to 0.300% by mass, 0.050 to 0.200% by mass, 0.100 to 0.200% by mass, or 0.100 to 0.180% by mass. The content of the silicone compound may be 0.200% by mass or more, 0.250% by mass or more, 0.300% by mass or more, or 0.350% by mass or more. The content of the silicone compound may be 0.150% by mass or less, 0.120% by mass or less, 0.100% by mass or less, 0.060% by mass or less, 0.050% by mass or less, 0.020% by mass or less, 0.012% by mass or less, 0.010% by mass or less, or 0.006% by mass or less.

The content of the silicone compound is preferably in the following range with respect to 100 parts by mass of the metal A. The content of the silicone compound is preferably 1.0×10³ parts by mass or more, 2.0×10³ parts by mass or more, 3.0×10³ parts by mass or more, 4.0×10³ parts by mass or more, 5.0×10³ parts by mass or more, 1.0×10⁴ parts by mass or more, 2.0×10⁴ parts by mass or more, 3.0×10⁴ parts by mass or more, 4.0×10⁴ parts by mass or more, 5.0×10⁴ parts by mass or more, or 6.0×10⁴ parts by mass or more, from the viewpoint of easily obtaining excellent tactile sensation (such as a slipping property improving effect) of the fiber for artificial hair. The content of the silicone compound is preferably 1.0×10⁶ parts by mass or less, 5.0×10⁵ parts by mass or less, 4.0×10⁵ parts by mass or less, 2.0×10⁵ parts by mass or less, 1.0×10⁵ parts by mass or less, 9.0×10⁴ parts by mass or less, 8.0×10⁴ parts by mass or less, or 7.0×10⁴ parts by mass or less, from the viewpoint of easily obtaining excellent tactile sensation (such as a stickiness suppressing effect) of the fiber for artificial hair. From these viewpoints, the content of the silicone compound is preferably 1.0×10³ to 1.0×10⁶ parts by mass, 1.0×10³ to 5.0×10⁵ parts by mass, 2.0×10³ to 5.0×10⁵ parts by mass, 2.0×10³ to 2.0×10⁵ parts by mass, or 1.0×10⁴ to 2.0×10⁵ parts by mass. The content of the silicone compound may be 7.0×10⁴ parts by mass or more, 8.0×10⁴ parts by mass or more, 9.0×10⁴ parts by mass or more, 1.0×10⁵ parts by mass or more, 2.0×10⁵ parts by mass or more, or 4.0×10⁴ parts by mass or more. The content of the silicone compound may be 6.0×10⁴ parts by mass or less, 5.0×10⁴ parts by mass or less, 4.0×10⁴ parts by mass or less, 3.0×10⁴ parts by mass or less, 2.0×10⁴ parts by mass or less, 1.0×10⁴ parts by mass or less, 5.0×10³ parts by mass or less, 4.0×10³ parts by mass or less, or 3.0×10³ parts by mass or less.

The fiber for artificial hair of the present embodiment may have other additive (excluding a component corresponding to the metal salt A, the antistatic agent, or the silicone compound) that is present in at least a part of the surface of the base fiber. Examples of such an additive include an antibacterial processing agent, a deodorant processing agent, an antifungal processing agent, a UV cutting agent, a softener, an SR processing agent, an aromatic processing agent, a flame retardant, an antifoaming agent, and fragrance. As the additive, an amine compound (for example, ethylenediaminetetraacetic acid (EDTA)), ammonium hydroxide, an alkali metal, polyoxyethylene alkyl ether, or the like may be used. In the fiber for artificial hair of the present embodiment, at least one selected from the group consisting of zeolite and zirconium carbide may not be present in the surface of the base fiber, or the base fiber may not contain at least one selected from the group consisting of zeolite and zirconium carbide.

The metal salt A, the antistatic agent, the silicone compound, and the additive mentioned above may be present at the mutually same place or at mutually different places on the surface of the base fiber, respectively. The fiber for artificial hair of the present embodiment may have a fiber treating agent that is present in at least a part of the surface of the base fiber or may be a fiber for artificial hair of which the surface is treated with a fiber treating agent. The fiber treating agent may contain the metal salt A, the antistatic agent, the silicone compound, the additive, or the like mentioned above.

The single fiber fineness of the fiber for artificial hair of the present embodiment is preferably in the following range after a stretching treatment. The single fiber fineness is preferably 20 decitex or more. The single fiber fineness is preferably 100 decitex or less. From these viewpoints, the single fiber fineness is preferably 20 to 100 decitex.

A method for producing a fiber for artificial hair of the present embodiment include a fiber treating step of bringing a base fiber and a metal salt A into contact with each other. In the fiber treating step, the antistatic agent, the silicone compound, the additive, or the like mentioned above, in addition to the metal salt A, may be brought into contact with the base fiber. In the fiber treating step, the base fiber and the above-mentioned fiber treating agent may be brought into contact with each other or respective components may be individually brought into contact with the base fiber.

In the case of using the fiber treating agent, the fiber treating agent can be applied to at least a part of the surface of the base fiber. In this case, a conventionally known means for applying a liquid to a fiber can be used. Examples thereof include a means for applying the fiber treating agent to the fiber for artificial hair by a roll having a surface to which the fiber treating agent has been attached (roll transfer method); a means for immersing the base fiber in a liquid tank storing the fiber treating agent; and a means for attaching the fiber treating agent to the base fiber with an applicator such as a brush and a paint brush.

The method for producing a fiber for artificial hair of the present embodiment may include a spinning step of spinning a composition containing a base fiber material to obtain a base fiber, before the fiber treating step. In the spinning step, the composition containing a base fiber material can be subjected to melt-spinning (melt-deformation).

The method for producing a fiber for artificial hair of the present embodiment may include a kneading step of melt-kneading a composition containing a base fiber material, before the spinning step. As an apparatus for performing melt-kneading, various general kneading machines can be used. Examples of the kneading machine include a single-screw extruder, a twin-screw extruder, a roll, a Banbury mixer, and a kneader.

The method for producing a fiber for artificial hair of the present embodiment may include a stretching step of subjecting the fiber (unstretched fiber) obtained in the spinning step to a stretching treatment, before the fiber treating step.

From the viewpoint that the strength development of the fiber is likely to occur, the stretch ratio in the stretching step is preferably 1.5 times or more, and more preferably 2.0 times or more. From the viewpoint that fiber breakage is less likely to occur at the time of the stretching treatment, the stretch ratio is preferably 5.0 times or less, and more preferably 4.0 times or less. From these viewpoints, the stretch ratio is preferably 1.5 to 5.0 times, and more preferably 2.0 to 4.0 times.

The stretching treatment may be carried out by a two-step method in which an unstretched fiber is first wound on a bobbin and then stretched in a step that is not continuous with the spinning step, or may be carried out by a direct spinning stretching method in which an unstretched fiber is stretched in a step continuous with the spinning step without being wound on a bobbin. The stretching treatment may be carried out by a one-stage stretching method of performing stretching once to a desired stretch ratio or may be carried out by a multistage stretching method of performing stretching to a desired stretch ratio by two or more times of stretching.

The temperature of the stretching treatment is preferably 80° C. to 120° C. When the temperature is 80° C. or higher, the strength of the fiber is likely to be sufficiently secured and fiber breakage is less likely to occur. When the temperature is 120° C. or lower, a suitable tactile sensation of the fiber is likely to be obtained.

The method for producing a fiber for artificial hair of the present embodiment may include a heat treatment step of heat-treating (annealing) the fiber (stretched fiber) obtained in the stretching step, after the stretching step. By performing the heat treatment step, the thermal shrinkage rate of the stretched fiber can be decreased.

The heat treatment temperature is preferably 100° C. or higher and more preferably 120° C. or higher. The heat treatment temperature is preferably 200° C. or lower and more preferably 150° C. or lower. The heat treatment may be carried out continuously after the stretching treatment or may be carried out after a while after winding the stretched fiber once.

A headdress article of the present embodiment has the fiber for artificial hair of the present embodiment. The headdress article of the present embodiment is an article that is wearable on and removable from the head portion, and the headdress article may be an embodiment composed of the fiber for artificial hair of the present embodiment (for example, a fiber bundle of the fiber for artificial hair). Examples of the headdress article include hairpieces, hair wigs, hair pieces, braid, hair extension hair, and attached hair.

Examples

Hereinafter, the present invention will be more specifically described by way of Experimental Examples; however, the present invention is not intended to be limited to these Experimental Examples. Hereinafter, a notation such as “3.0E-05” or “1.0E+10” means “3.0×10⁻⁵”, “1.0×10¹⁰”, or the like.

<Production of Fiber for Evaluation>

A vinyl chloride-based fiber (fiber using polyvinyl chloride (TAIYO VINYL CORPORATION, trade name: TH-700)) was prepared as a base fiber. The average fineness of the fibers was 55 to 70 decitex. The average fineness was determined as an average value of fineness of 100 fibers.

Subsequently, a fiber treating agent was prepared by mixing components shown in Tables 1 to 3. The following reagents were used as components shown in each table.

Metal salt A (Ag): DuPont, trade name “SILVADUR 930 Flex Antimicrobial”, an aqueous dispersion containing a silver ion, ammonium hydroxide, and a polymer (silver ion amount: 0.098% by mass, ammonium hydroxide amount: 0.25 to 1.0% by mass, polymer: a copolymer having a structural unit derived from 1-vinylimidazole and a structural unit derived from poly(ethylene glycol) methyl ether methacrylate (a polymer compound forming a metal salt with a silver ion))

Metal salt B (Zn): In-house preparation, an aqueous dispersion containing a zinc ion, ammonium hydroxide, and a polymer (zinc ion amount: 0.098% by mass, ammonium hydroxide amount: 0.25 to 1.0% by mass, polymer: a copolymer having a structural unit derived from 1-vinylimidazole and a structural unit derived from poly(ethylene glycol) methyl ether methacrylate (a polymer compound forming a metal salt with a zinc ion))

Metal salt C (Cu): In-house preparation, an aqueous dispersion containing a copper ion, ammonium hydroxide, and a polymer (copper ion amount: 0.098% by mass, ammonium hydroxide amount: 0.25 to 1.0% by mass, polymer: a copolymer having a structural unit derived from 1-vinylimidazole and a structural unit derived from poly(ethylene glycol) methyl ether methacrylate (a polymer compound forming a metal salt with a copper ion))

Antistatic agent: NIPPON NYUKAZAI CO., LTD., trade name “AMINOION AS300”, an ionic liquid containing 98% by mass or more of an amine salt containing ions having an amino group

Tactile sensation adjuster: YOSHIMURA OIL CHEMICAL Co., Ltd., trade name “TCS-382”, a silicone emulsion containing 50% by mass of a silicone compound (amino-modified silicone) and polyoxyethylene alkyl ether in total (content of amino-modified silicone: 44% by mass)

The above-mentioned base fiber was stretched at 100° C., and then the above-mentioned fiber treating agent was applied to the base fiber by a roll transfer method. As roll transfer conditions, the radius of the roll was 125 mm, the roll was immersed in the fiber treating agent with a height of 20 mm from the lower end of the roll, and the roll rotation speed was 8 n/min. Thereafter, annealing was performed at 120° C., and a fiber for evaluation (fiber for artificial hair) having a single fiber fineness of 20 to 100 decitex was obtained. The stretch ratio was 3.25 times, and the relaxation ratio during annealing was 25%. The relaxation ratio during annealing is a value calculated by the formula: “(Circumference of the outlet nearest portion of the roller of the annealing furnace)/(Circumference of the inlet nearest portion of the roller of the annealing furnace)”.

The amounts (unit: % by mass) of the metal of the metal salt, the antistatic agent, and the silicone compound attached to the surface of the fiber for evaluation are shown as the contents of active ingredients in the fiber for evaluation in each table. Assuming that the solid content in a decrement of the fiber treating agent is attached to the surface of the fiber for evaluation, the attached amount was calculated by the formula:

“((Decrement of the fiber treating agent in the fiber treating step×(Active ingredient ratio [%] of each reagent in the fiber treating agent/100))/Total amount of the fiber for evaluation)×100”.

<Evaluation>

The antibacterial activity, the antistatic property, and the tactile sensation were evaluated using the above-mentioned fiber for evaluation. The results are shown in Tables 1 to 3.

(Antibacterial Activity)

The antibacterial activity of the fiber for evaluation was evaluated based on JIS Z 2801. Escherichia coli and Staphylococcus aureus were used as test bacteria, and a difference in the number of viable bacteria (antibacterially active value) before and after the bacteria was left to stand at 35° C. for 24 hours was measured. The antibacterial activity was evaluated based on an average value of three times measurements. The average value is shown in each table.

(Antistatic Property)

The above-mentioned fibers for evaluation were bundled to obtain a fiber bundle having a length of 250 mm and a mass of 20 g. Subsequently, the fiber bundle was left to stand for 24 hours in the environment of 23° C. and 50% RH, and then the surface resistance value was measured under the condition of an applied voltage of 10 V using a digital ultra-high resistance/micro current meter (ADVANTEST CORPORATION, trade name: R8340). The antistatic property was evaluated based on an average value of five times measurements. The average value is shown in each table.

(Tactile Sensation)

The slipping property and the stickiness were evaluated as the tactile sensation. The above-mentioned fibers for evaluation were bundled to obtain a fiber bundle having a length of 250 mm and a mass of 20 g. The slipping property and the stickiness of the fiber bundle were determined based on the following criteria by touching of ten technicians for treatment of the fiber for artificial hair (work experience: 5 years or longer).

[Slipping Property]

A: All the technicians evaluated that the slipping property was favorable.

B: The proportion of the technicians who evaluated that the slipping property was favorable was 90% or more and less than 100%.

C: The proportion of the technicians who evaluated that the slipping property was favorable was 70% or more and less than 90%.

D: The proportion of the technicians who evaluated that the slipping property was favorable was less than 70%.

[Stickiness]

A: All the technicians evaluated that the tactile sensation was favorable without stickiness.

B: The proportion of the technicians who evaluated that the tactile sensation was favorable without stickiness was 90% or more and less than 100%.

C: The proportion of the technicians who evaluated that the tactile sensation was favorable without stickiness was 70% or more and less than 90%.

D: The proportion of the technicians who evaluated that the tactile sensation was favorable without stickiness was less than 70%.

TABLE 1 Experimental Example 1 2 3 4 5 6 7 8 9 Content in fiber Metal salt A (Ag) 1 3 10 17 20 treating agent Metal salt B (Zn) 3 17 [parts by mass] Metal salt C (Cu) 3 17 AS300 1 1 1 1 1 1 1 TCS-382 10 10 10 10 1 10 10 10 10 Water 88 86 79 72 69 86 72 86 72 Content of active Metal 3.0E−05 7.1E−05 2.7E−04 4.5E−04 5.5E−03 7.1E−05 4.5E−04 7.1E−05 4.5E−04 ingredient in fiber Antistatic agent 0.267 0.267 0.267 0.267 0.267 0.267 0.267 0.267 0.267 for evaluation Silicone 0.120 0.120 0.120 0.120 0.120 0.120 0.120 0.120 0.120 [% by mass] compound Antibacterial Escherichia coli 2 5 ≥6 ≥6 ≥6 3 5 3 5 activity Staphylococcus 0.5 3 5 5 ≥6 2 4 2 4 aureus Antistatic Surface resistance 1.0E+10 1.0E+10 1.0E+10 1.0E+10 1.0E+10 1.0E+10 1.0E+10 1.0E+10 1.0E+10 property value [Ω] Tactile Slipping property B B B B C B B B B sensation Stickiness B B B B D B B B B

TABLE 2 Experimental Example 10 11 12 13 14 Content in fiber Metal salt A (Ag) 10 10 10 10 10 treating agent AS300 0.05 0.1 0.5 1.4 2 [parts by mass] TCS-382 10 10 10 10 10 Water 79.95 79.9 79.5 78.6 78 Content of active Metal 2.7E−04 2.7E−04 2.7E−04 2.7E−04 2.7E−04 ingredient in fiber Antistatic agent 0.015 0.030 0.150 0.350 0.600 for evaluation Silicone 0.120 0.120 0.120 0.120 0.120 [% by mass] compound Antibacterial Escherichia coli ≥6 ≥6 ≥6 ≥6 ≥6 activity Staphylococcus 5 5 5 5 5 aureus Antistatic Surface resistance 5.0E+10 1.0E+10 1.0E+10 2.0E+09 2.0E+09 property value [Ω] Tactile Slipping property B B B B B sensation Stickiness B B B B C

TABLE 3 Experimental Example 15 16 17 18 19 20 Content in fiber Metal salt A (Ag) 10 10 10 10 10 10 treating agent AS300 1.4 1.4 1.4 1.4 1.4 1.4 [parts by mass] TCS-382 0.5 1 5 15 20 30 Water 88.1 87.6 83.6 73.6 68.6 58.6 Content of active Metal 2.7E−04 2.7E−04 2.7E−04 2.7E−04 2.7E−04 2.7E−04 ingredient in fiber Antistatic agent 0.350 0.350 0.350 0.350 0.350 0.350 for evaluation Silicone 0.006 0.012 0.060 0.180 0.240 0.360 [% by mass] compound Antibacterial Escherichia coli ≥6 ≥6 ≥6 ≥6 ≥6 ≥6 activity Staphylococcus 5 5 5 5 5 5 aureus Antistatic Surface resistance 2.0E+09 2.0E+09 2.0E+09 2.0E+09 2.0E+09 2.0E+09 property value [Ω] Tactile Slipping property B B B A A A sensation Stickiness C B B A B C

As shown in each table, it is found that, by using a metal salt containing at least one metal selected from the group consisting of silver, zinc, and copper as the metal salt of the polymer compound, the antibacterial activity can be imparted to the fiber for artificial hair. 

1. A fiber for artificial hair, comprising a base fiber and a metal salt of a polymer compound that is present in at least a part of a surface of the base fiber, wherein the metal salt contains at least one metal selected from the group consisting of silver, zinc, and copper.
 2. The fiber for artificial hair according to claim 1, wherein the metal salt contains silver.
 3. The fiber for artificial hair according to claim 2, wherein a content of the metal is 5.0×10⁵ to 5.0×10⁻³% by mass based on the total mass of the fiber for artificial hair.
 4. The fiber for artificial hair according to claim 2, further comprising an antistatic agent that is present in at least a part of the surface of the base fiber, wherein a content of the antistatic agent is 0.020 to 0.400% by mass based on the total mass of the fiber for artificial hair.
 5. The fiber for artificial hair according to claim 2, further comprising a silicone compound that is present in at least a part of the surface of the base fiber, wherein a content of the silicone compound is 0.010 to 0.300% by mass based on the total mass of the fiber for artificial hair.
 6. The fiber for artificial hair according to claim 2, wherein the base fiber contains a vinyl chloride-based resin.
 7. A headdress article comprising the fiber for artificial hair according to claim
 2. 8. The fiber for artificial hair according to claim 1, wherein the metal salt contains zinc.
 9. The fiber for artificial hair according to claim 8, wherein a content of the metal is 5.0×10⁻⁵ to 5.0×10⁻³% by mass based on the total mass of the fiber for artificial hair.
 10. The fiber for artificial hair according to claim 8, further comprising an antistatic agent that is present in at least a part of the surface of the base fiber, wherein a content of the antistatic agent is 0.020 to 0.400% by mass based on the total mass of the fiber for artificial hair.
 11. The fiber for artificial hair according to claim 8, further comprising a silicone compound that is present in at least a part of the surface of the base fiber, wherein a content of the silicone compound is 0.010 to 0.300% by mass based on the total mass of the fiber for artificial hair.
 12. The fiber for artificial hair according to claim 8, wherein the base fiber contains a vinyl chloride-based resin.
 13. A headdress article comprising the fiber for artificial hair according to claim
 8. 14. The fiber for artificial hair according to claim 1, wherein the metal salt contains copper.
 15. The fiber for artificial hair according to claim 14, wherein a content of the metal is 5.0×10⁻⁵ to 5.0×10⁻³% by mass based on the total mass of the fiber for artificial hair.
 16. The fiber for artificial hair according to claim 14, further comprising an antistatic agent that is present in at least a part of the surface of the base fiber, wherein a content of the antistatic agent is 0.020 to 0.400% by mass based on the total mass of the fiber for artificial hair.
 17. The fiber for artificial hair according to claim 14, further comprising a silicone compound that is present in at least a part of the surface of the base fiber, wherein a content of the silicone compound is 0.010 to 0.300% by mass based on the total mass of the fiber for artificial hair.
 18. The fiber for artificial hair according to claim 14, wherein the base fiber contains a vinyl chloride-based resin.
 19. A headdress article comprising the fiber for artificial hair according to claim
 14. 